2-74483337-C-T

Variant names:

• chr2-74483337-C-T
• rs761654775
• NM_022492.6:c.56C>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_022492.6(TTC31):​c.56C>T​(p.Pro19Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000743 in 1,614,062 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: TTC31 NM_022492.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.02
• Publications: 0 publications found

Genes affected

TTC31 (HGNC:25759): (tetratricopeptide repeat domain 31)

CCDC142 (HGNC:25889): (coiled-coil domain containing 142)

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.12256014).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTC31	NM_022492.6	c.56C>T	p.Pro19Leu	missense_variant	Exon 2 of 13	ENST00000233623.11	NP_071937.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTC31	ENST00000233623.11	c.56C>T	p.Pro19Leu	missense_variant	Exon 2 of 13	1	NM_022492.6	ENSP00000233623.6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000321 AC: 8 AN: 249580 AF XY: 0.0000222

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000232

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461868 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 727232

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.000224 AC: 10 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5750

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74368

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41446

American (AMR) AF: 0.0000655 AC: 1 AN: 15268

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68036

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.00000827 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Feb 18, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.56C>T (p.P19L) alteration is located in exon 2 (coding exon 2) of the TTC31 gene. This alteration results from a C to T substitution at nucleotide position 56, causing the proline (P) at amino acid position 19 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.092
BayesDel_addAF	Benign	-0.41	T
BayesDel_noAF	Benign	-0.53
CADD	Benign	14
DANN	Uncertain	0.99
DEOGEN2	Benign	0.0081	.;.;T
Eigen	Benign	-0.59
Eigen_PC	Benign	-0.59
FATHMM_MKL	Benign	0.042	N
LIST_S2	Benign	0.79	T;T;T
M_CAP	Benign	0.0079	T
MetaRNN	Benign	0.12	T;T;T
MetaSVM	Benign	-0.93	T
MutationAssessor	Benign	1.6	L;.;L
PhyloP100		1.0
PrimateAI	Benign	0.28	T
PROVEAN	Pathogenic	-5.2	.;D;N
REVEL	Benign	0.090
Sift	Uncertain	0.0040	.;D;D
Sift4G	Uncertain	0.0080	D;D;D
Polyphen		0.0030	.;.;B
Vest4		0.24
MutPred		0.41		Gain of sheet (P = 0.0166);Gain of sheet (P = 0.0166);Gain of sheet (P = 0.0166);
MVP		0.57
MPC		0.087
ClinPred		0.24	T
GERP RS		4.0
PromoterAI		-0.017	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.051
gMVP		0.13
Mutation Taster		=98/2	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs761654775; hg19: chr2-74710464;